The present invention is with respect to a process and apparatus for debittering bitter lupin seed.
The bitter lupin is a crop plant that has been grown even in ancient Egypt and then later all over the Mediterranean Region and in South America. On account of the high content in its seed of completely digestible protein of 40% and over and its oil content of 15 to 20%, it was and is esteemed as a nutrient for man and animals.
However before bitter lupin seed may be used as a food for man or animals it has to be freed of its bitter substances, this being not only for freeing it of the bitter taste but furthermore to make certain that the bitter substances are not the cause of the so-called lupin disease, that is specially likely in the case of domestic animals.
In one well-known process for freeing lupin seed of bitter substances, the lupin seed is firstly boiled and then steeped in water for up to 48 hours. The shortcoming of this process is that it is complex and high in price to undertake and that there is a marked loss in the food value of the lupin seed. Furthermore large amounts of water are needed and contamination of the rivers or the like into which the waste is run may well be a cause of trouble. There are futhermore debittering processes run on solvents other than water, but such processes have serious shortcomings.
In addition to the use of bitter lupin seed as a food for man and a feedstuff for animals, the seed has futhermore been used in a milled form as a material for promoting the growth of plants. The effects of milled lupin seed on the growth of plants are however small.